1. Field
Aspects of embodiments according to the present invention relate to a display device and a driving method thereof.
2. Description of Related Art
In recent years, various flat panel displays, with reduced weight and volume compared to that of cathode ray tube devices, have been developed. Some examples of the flat panel display devices include a liquid crystal display (LCD), a field emission display (FED), a plasma display panel (PDP), and an organic light emitting display.
Among the various flat panel displays, the organic light emitting display displays an image by using organic light emitting diodes (OLEDs) which generate light by the recombination of electrons and holes. The organic light emitting display has fast response, low power consumption, and excellent emission efficiency, luminance, and viewing angle. The organic light emitting diode (OLED) display may be classified as a passive matrix organic light emitting diode (PMOLED) display or an active matrix organic light emitting diode (AMOLED) display, according to a driving method of the OLEDs.
In the passive matrix type (PMOLED), an anode and a cathode are formed crossing each other and a cathode line and an anode line are selected to be driven. In the active matrix type (AMOLED), a thin film transistor and a capacitor are integrated in each pixel to maintain a voltage by the capacitance of the capacitor. The passive matrix type has a simple structure and thus, it has a low cost. However, the passive matrix type is not as suitable for fabricating large sized or high-resolution panels. The active matrix type, on the other hand, enables the fabrication of large-sized and high-resolution panels. However, its control method is more complex and its cost is relatively high compared to PMOLED displays. The AMOLED display, which selectively lights every unit pixel, has been widely used.
In newer AMOLED display devices, such as a portable communication device or digital imaging device, bi-directional driving is being proposed as a way to provide improved viewing angle characteristics of the display panel, as well as to allow the display panel to be reversed depending on installation positions. However, the display device including the bi-directional scan driver and a corresponding pixel circuit may have the problem of an increase in panel D/S because of an increase in circuit complexity and an increase in the number of elements. Accordingly, there is a demand for the development of a driving method of pixels that are driven by bi-directional scanning, in association with a circuit design of a scan driver for reducing the overall panel D/S in the display device by decreasing the driving circuit area of the bi-directional scan driver.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.